Evidence of a 2D Fermi surface due to surface states in a p-type metallic Bi₂Te₃

We present a systematic quantum oscillations study on a metallic, p-type Bi₂Te₃ topological single crystal in magnetic fields up to B = 7 T. The maxima/minima positions of oscillations measured at different tilt angles align to one another when plotted as a function of the normal component of magnetic field, confirming the presence of the 2D Fermi surface. Additionally, the Berry phase, β = 0.4 ± 0.05 obtained from the Landau level fan plot, is very close to the theoretical value of 0.5 for the Dirac particles, confirming the presence of topological surface states in the Bi₂Te₃ single crystal. Using the Lifshitz-Kosevich analyses, the Fermi energy is estimated to be meV, which is lower than that of other bismuth-based topological systems. The detection of surface states in the Bi₂Te₃ crystal can be explained by our previous hypothesis of the lower position of the Fermi surface that cuts the 'M'-shaped valence band maxima. As a result, the bulk state frequency is shifted to higher magnetic fields, which allows measurement of the surface states signal at low magnetic fields.